title: Urinary-cell mRNA profile and acute cellular rejection in kidney allografts.
abstract: BACKGROUND
  The standard test for the diagnosis of acute rejection in kidney transplants is the renal biopsy. Noninvasive tests would be preferable.
  
  
  METHODS
  We prospectively collected 4300 urine specimens from 485 kidney-graft recipients from day 3 through month 12 after transplantation. Messenger RNA (mRNA) levels were measured in urinary cells and correlated with allograft-rejection status with the use of logistic regression.
  
  
  RESULTS
  A three-gene signature of 18S ribosomal (rRNA)-normalized measures of CD3ε mRNA and interferon-inducible protein 10 (IP-10) mRNA, and 18S rRNA discriminated between biopsy specimens showing acute cellular rejection and those not showing rejection (area under the curve [AUC], 0.85; 95% confidence interval [CI], 0.78 to 0.91; P<0.001 by receiver-operating-characteristic curve analysis). The cross-validation estimate of the AUC was 0.83 by bootstrap resampling, and the Hosmer-Lemeshow test indicated good fit (P=0.77). In an external-validation data set, the AUC was 0.74 (95% CI, 0.61 to 0.86; P<0.001) and did not differ significantly from the AUC in our primary data set (P=0.13). The signature distinguished acute cellular rejection from acute antibody-mediated rejection and borderline rejection (AUC, 0.78; 95% CI, 0.68 to 0.89; P<0.001). It also distinguished patients who received anti-interleukin-2 receptor antibodies from those who received T-cell-depleting antibodies (P<0.001) and was diagnostic of acute cellular rejection in both groups. Urinary tract infection did not affect the signature (P=0.69). The average trajectory of the signature in repeated urine samples remained below the diagnostic threshold for acute cellular rejection in the group of patients with no rejection, but in the group with rejection, there was a sharp rise during the weeks before the biopsy showing rejection (P<0.001).
  
  
  CONCLUSIONS
  A molecular signature of CD3ε mRNA, IP-10 mRNA, and 18S rRNA levels in urinary cells appears to be diagnostic and prognostic of acute cellular rejection in kidney allografts. (Funded by the National Institutes of Health and others.).
authors.affiliation: Weill Cornell Medical College, New York, NY, USA. msuthan@med.cornell.edu
authors.forename: Manikkam
authors.initials: M
authors.lastname: Suthanthiran
authors.forename: Joseph E
authors.initials: JE
authors.lastname: Schwartz
authors.forename: Ruchuang
authors.initials: R
authors.lastname: Ding
authors.forename: Michael
authors.initials: M
authors.lastname: Abecassis
authors.forename: Darshana
authors.initials: D
authors.lastname: Dadhania
authors.forename: Benjamin
authors.initials: B
authors.lastname: Samstein
authors.forename: Stuart J
authors.initials: SJ
authors.lastname: Knechtle
authors.forename: John
authors.initials: J
authors.lastname: Friedewald
authors.forename: Yolanda T
authors.initials: YT
authors.lastname: Becker
authors.forename: Vijay K
authors.initials: VK
authors.lastname: Sharma
authors.forename: Nikki M
authors.initials: NM
authors.lastname: Williams
authors.forename: Christina S
authors.initials: CS
authors.lastname: Chang
authors.forename: Christine
authors.initials: C
authors.lastname: Hoang
authors.forename: Thangamani
authors.initials: T
authors.lastname: Muthukumar
authors.forename: Phyllis
authors.initials: P
authors.lastname: August
authors.forename: Karen S
authors.initials: KS
authors.lastname: Keslar
authors.forename: Robert L
authors.initials: RL
authors.lastname: Fairchild
authors.forename: Donald E
authors.initials: DE
authors.lastname: Hricik
authors.forename: Peter S
authors.initials: PS
authors.lastname: Heeger
authors.forename: Leiya
authors.initials: L
authors.lastname: Han
authors.forename: Jun
authors.initials: J
authors.lastname: Liu
authors.forename: Michael
authors.initials: M
authors.lastname: Riggs
authors.forename: David N
authors.initials: DN
authors.lastname: Ikle
authors.forename: Nancy D
authors.initials: ND
authors.lastname: Bridges
authors.forename: Abraham
authors.initials: A
authors.lastname: Shaked
mesh_terms: D000208:Acute Disease; D000328:Adult; D019540:Area Under Curve; D054357:Chemokine CXCL10 / Q000235:genetics* / Q000652:urine; D005260:Female; D006084:Graft Rejection / Q000175:diagnosis* / Q000235:genetics; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics* / Q000652:urine; D016030:Kidney Transplantation; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012318:RNA Polymerase I; D012333:RNA, Messenger / Q000652:urine*; D012335:RNA, Ribosomal / Q000652:urine*; D012337:RNA, Ribosomal, 18S / Q000652:urine; D012372:ROC Curve; D060888:Real-Time Polymerase Chain Reaction; D012680:Sensitivity and Specificity; D059467:Transcriptome
chemical_list: C114753:CXCL10 protein, human; D054357:Chemokine CXCL10; D047908:Intracellular Signaling Peptides and Proteins; D012333:RNA, Messenger; D012335:RNA, Ribosomal; D012337:RNA, Ribosomal, 18S; C119975:POLR1G protein, human; D012318:RNA Polymerase I